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Forum Discussion

DB's avatar
DB
Icon for Nimbostratus rankNimbostratus
May 29, 2009

X-Forwarded For equivelent for SMTP?

I'm running SMTP through LTM to Exchange 2008 servers, but due to my network architecture I have to autosnat the source IP to that of the F5. My Exchange servers therefore lose visibility of the origi...
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slomah_85788's avatar
slomah_85788
Icon for Nimbostratus rankNimbostratus
Jun 19, 2009
Thanks hoolio,

 

It looks like that I have to change to the default gateway on the mail server to the BIG-IP, or I'll try either npath or vlan group.
The-messenger's avatar
The-messenger
Icon for Cirrostratus rankCirrostratus
Mar 02, 2017

I'm still pretty new to Big-IP, only a year or so but I've worked in the messaging world for many years. This issue of getting the original client ip is not new to the messaging world but for many reasons setting the f5 as the default gateway is not a good solution.

 

  • the source ip is needed in the message tracking logs but the ip of the f5 device is also needed in the logs. If your logs show inaccurate information you could have trouble with email discoveries. Messaging logs should show both the f5 and the sending server address.

We really need an x-header value! SMTP is capable of working with x-header values, every filtering system out there uses x-headers to react to messages, log messages and more. A stream rule could be the answer.